/*
 * qrencode - QR Code encoder
 *
 * Copyright (C) 2006-2012 Kentaro Fukuchi <kentaro@fukuchi.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "qrencode.h"
#include "qrspec.h"
#include "mqrspec.h"
#include "bitstream.h"
#include "qrinput.h"
#include "rscode.h"
#include "split.h"
#include "mask.h"
#include "mmask.h"
#include "config.h"

/******************************************************************************
 * Raw code
 *****************************************************************************/

typedef struct
{
    int dataLength;
    unsigned char* data;
    int eccLength;
    unsigned char* ecc;
} RSblock;

typedef struct
{
    int version;
    int dataLength;
    int eccLength;
    unsigned char* datacode;
    unsigned char* ecccode;
    int b1;
    int blocks;
    RSblock* rsblock;
    int count;
} QRRawCode;

static void RSblock_initBlock(RSblock* block, int dl, unsigned char* data, int el, unsigned char* ecc, RS* rs)
{
    block->dataLength = dl;
    block->data = data;
    block->eccLength = el;
    block->ecc = ecc;

    encode_rs_char(rs, data, ecc);
}

static int RSblock_init(RSblock* blocks, int spec[5], unsigned char* data, unsigned char* ecc)
{
    int i;
    RSblock* block;
    unsigned char* dp, *ep;
    RS* rs;
    int el, dl;

    dl = QRspec_rsDataCodes1(spec);
    el = QRspec_rsEccCodes1(spec);
    rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);

    if (rs == NULL)
        return -1;

    block = blocks;
    dp = data;
    ep = ecc;

    for (i = 0; i < QRspec_rsBlockNum1(spec); i++)
    {
        RSblock_initBlock(block, dl, dp, el, ep, rs);
        dp += dl;
        ep += el;
        block++;
    }

    if (QRspec_rsBlockNum2(spec) == 0)
        return 0;

    dl = QRspec_rsDataCodes2(spec);
    el = QRspec_rsEccCodes2(spec);
    rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);

    if (rs == NULL)
        return -1;

    for (i = 0; i < QRspec_rsBlockNum2(spec); i++)
    {
        RSblock_initBlock(block, dl, dp, el, ep, rs);
        dp += dl;
        ep += el;
        block++;
    }

    return 0;
}

__STATIC void QRraw_free(QRRawCode* raw);
__STATIC QRRawCode* QRraw_new(QRinput* input)
{
    QRRawCode* raw;
    int spec[5], ret;

    raw = (QRRawCode*)malloc(sizeof(QRRawCode));

    if (raw == NULL)
        return NULL;

    raw->datacode = QRinput_getByteStream(input);

    if (raw->datacode == NULL)
    {
        free(raw);
        return NULL;
    }

    QRspec_getEccSpec(input->version, input->level, spec);

    raw->version = input->version;
    raw->b1 = QRspec_rsBlockNum1(spec);
    raw->dataLength = QRspec_rsDataLength(spec);
    raw->eccLength = QRspec_rsEccLength(spec);
    raw->ecccode = (unsigned char*)malloc(raw->eccLength);

    if (raw->ecccode == NULL)
    {
        free(raw->datacode);
        free(raw);
        return NULL;
    }

    raw->blocks = QRspec_rsBlockNum(spec);
    raw->rsblock = (RSblock*)calloc(raw->blocks, sizeof(RSblock));

    if (raw->rsblock == NULL)
    {
        QRraw_free(raw);
        return NULL;
    }

    ret = RSblock_init(raw->rsblock, spec, raw->datacode, raw->ecccode);

    if (ret < 0)
    {
        QRraw_free(raw);
        return NULL;
    }

    raw->count = 0;

    return raw;
}

/**
 * Return a code (byte).
 * This function can be called iteratively.
 * @param raw raw code.
 * @return code
 */
__STATIC unsigned char QRraw_getCode(QRRawCode* raw)
{
    int col, row;
    unsigned char ret;

    if (raw->count < raw->dataLength)
    {
        row = raw->count % raw->blocks;
        col = raw->count / raw->blocks;

        if (col >= raw->rsblock[0].dataLength)
        {
            row += raw->b1;
        }

        ret = raw->rsblock[row].data[col];
    }
    else if (raw->count < raw->dataLength + raw->eccLength)
    {
        row = (raw->count - raw->dataLength) % raw->blocks;
        col = (raw->count - raw->dataLength) / raw->blocks;
        ret = raw->rsblock[row].ecc[col];
    }
    else
    {
        return 0;
    }

    raw->count++;
    return ret;
}

__STATIC void QRraw_free(QRRawCode* raw)
{
    if (raw != NULL)
    {
        free(raw->datacode);
        free(raw->ecccode);
        free(raw->rsblock);
        free(raw);
    }
}

/******************************************************************************
 * Raw code for Micro QR Code
 *****************************************************************************/

typedef struct
{
    int version;
    int dataLength;
    int eccLength;
    unsigned char* datacode;
    unsigned char* ecccode;
    RSblock* rsblock;
    int oddbits;
    int count;
} MQRRawCode;

__STATIC void MQRraw_free(MQRRawCode* raw);
__STATIC MQRRawCode* MQRraw_new(QRinput* input)
{
    MQRRawCode* raw;
    RS* rs;

    raw = (MQRRawCode*)malloc(sizeof(MQRRawCode));

    if (raw == NULL)
        return NULL;

    raw->version = input->version;
    raw->dataLength = MQRspec_getDataLength(input->version, input->level);
    raw->eccLength = MQRspec_getECCLength(input->version, input->level);
    raw->oddbits = raw->dataLength * 8 - MQRspec_getDataLengthBit(input->version, input->level);
    raw->datacode = QRinput_getByteStream(input);

    if (raw->datacode == NULL)
    {
        free(raw);
        return NULL;
    }

    raw->ecccode = (unsigned char*)malloc(raw->eccLength);

    if (raw->ecccode == NULL)
    {
        free(raw->datacode);
        free(raw);
        return NULL;
    }

    raw->rsblock = (RSblock*)calloc(1, sizeof(RSblock));

    if (raw->rsblock == NULL)
    {
        MQRraw_free(raw);
        return NULL;
    }

    rs = init_rs(8, 0x11d, 0, 1, raw->eccLength, 255 - raw->dataLength - raw->eccLength);

    if (rs == NULL)
    {
        MQRraw_free(raw);
        return NULL;
    }

    RSblock_initBlock(raw->rsblock, raw->dataLength, raw->datacode, raw->eccLength, raw->ecccode, rs);

    raw->count = 0;

    return raw;
}

/**
 * Return a code (byte).
 * This function can be called iteratively.
 * @param raw raw code.
 * @return code
 */
__STATIC unsigned char MQRraw_getCode(MQRRawCode* raw)
{
    unsigned char ret;

    if (raw->count < raw->dataLength)
    {
        ret = raw->datacode[raw->count];
    }
    else if (raw->count < raw->dataLength + raw->eccLength)
    {
        ret = raw->ecccode[raw->count - raw->dataLength];
    }
    else
    {
        return 0;
    }

    raw->count++;
    return ret;
}

__STATIC void MQRraw_free(MQRRawCode* raw)
{
    if (raw != NULL)
    {
        free(raw->datacode);
        free(raw->ecccode);
        free(raw->rsblock);
        free(raw);
    }
}


/******************************************************************************
 * Frame filling
 *****************************************************************************/

typedef struct
{
    int width;
    unsigned char* frame;
    int x, y;
    int dir;
    int bit;
    int mqr;
} FrameFiller;

static FrameFiller* FrameFiller_new(int width, unsigned char* frame, int mqr)
{
    FrameFiller* filler;

    filler = (FrameFiller*)malloc(sizeof(FrameFiller));

    if (filler == NULL)
        return NULL;

    filler->width = width;
    filler->frame = frame;
    filler->x = width - 1;
    filler->y = width - 1;
    filler->dir = -1;
    filler->bit = -1;
    filler->mqr = mqr;

    return filler;
}

static unsigned char* FrameFiller_next(FrameFiller* filler)
{
    unsigned char* p;
    int x, y, w;

    if (filler->bit == -1)
    {
        filler->bit = 0;
        return filler->frame + filler->y * filler->width + filler->x;
    }

    x = filler->x;
    y = filler->y;
    p = filler->frame;
    w = filler->width;

    if (filler->bit == 0)
    {
        x--;
        filler->bit++;
    }
    else
    {
        x++;
        y += filler->dir;
        filler->bit--;
    }

    if (filler->dir < 0)
    {
        if (y < 0)
        {
            y = 0;
            x -= 2;
            filler->dir = 1;

            if (!filler->mqr && x == 6)
            {
                x--;
                y = 9;
            }
        }
    }
    else
    {
        if (y == w)
        {
            y = w - 1;
            x -= 2;
            filler->dir = -1;

            if (!filler->mqr && x == 6)
            {
                x--;
                y -= 8;
            }
        }
    }

    if (x < 0 || y < 0)
        return NULL;

    filler->x = x;
    filler->y = y;

    if (p[y * w + x] & 0x80)
    {
        // This tail recursion could be optimized.
        return FrameFiller_next(filler);
    }

    return &p[y * w + x];
}

#ifdef WITH_TESTS
extern unsigned char* FrameFiller_test(int version)
{
    int width;
    unsigned char* frame, *p;
    FrameFiller* filler;
    int i, length;

    width = QRspec_getWidth(version);
    frame = QRspec_newFrame(version);

    if (frame == NULL)
        return NULL;

    filler = FrameFiller_new(width, frame, 0);

    if (filler == NULL)
    {
        free(frame);
        return NULL;
    }

    length = QRspec_getDataLength(version, QR_ECLEVEL_L) * 8
             + QRspec_getECCLength(version, QR_ECLEVEL_L) * 8
             + QRspec_getRemainder(version);

    for (i = 0; i < length; i++)
    {
        p = FrameFiller_next(filler);

        if (p == NULL)
        {
            free(filler);
            free(frame);
            return NULL;
        }

        *p = (unsigned char)(i & 0x7f) | 0x80;
    }

    free(filler);
    return frame;
}

extern unsigned char* FrameFiller_testMQR(int version)
{
    int width;
    unsigned char* frame, *p;
    FrameFiller* filler;
    int i, length;

    width = MQRspec_getWidth(version);
    frame = MQRspec_newFrame(version);

    if (frame == NULL)
        return NULL;

    filler = FrameFiller_new(width, frame, 1);

    if (filler == NULL)
    {
        free(frame);
        return NULL;
    }

    length = MQRspec_getDataLengthBit(version, QR_ECLEVEL_L)
             + MQRspec_getECCLength(version, QR_ECLEVEL_L) * 8;

    for (i = 0; i < length; i++)
    {
        p = FrameFiller_next(filler);

        if (p == NULL)
        {
            fprintf(stderr, "Frame filler run over the frame!\n");
            free(filler);
            return frame;
        }

        *p = (unsigned char)(i & 0x7f) | 0x80;
    }

    free(filler);
    return frame;
}
#endif


/******************************************************************************
 * QR-code encoding
 *****************************************************************************/

__STATIC QRcode* QRcode_new(int version, int width, unsigned char* data)
{
    QRcode* qrcode;

    qrcode = (QRcode*)malloc(sizeof(QRcode));

    if (qrcode == NULL)
        return NULL;

    qrcode->version = version;
    qrcode->width = width;
    qrcode->data = data;

    return qrcode;
}

void QRcode_free(QRcode* qrcode)
{
    if (qrcode != NULL)
    {
        free(qrcode->data);
        free(qrcode);
    }
}

__STATIC QRcode* QRcode_encodeMask(QRinput* input, int mask)
{
    int width, version;
    QRRawCode* raw;
    unsigned char* frame, *masked, *p, code, bit;
    FrameFiller* filler;
    int i, j;
    QRcode* qrcode = NULL;

    if (input->mqr)
    {
        errno = EINVAL;
        return NULL;
    }

    if (input->version < 0 || input->version > QRSPEC_VERSION_MAX)
    {
        errno = EINVAL;
        return NULL;
    }

    if (input->level > QR_ECLEVEL_H)
    {
        errno = EINVAL;
        return NULL;
    }

    raw = QRraw_new(input);

    if (raw == NULL)
        return NULL;

    version = raw->version;
    width = QRspec_getWidth(version);
    frame = QRspec_newFrame(version);

    if (frame == NULL)
    {
        QRraw_free(raw);
        return NULL;
    }

    filler = FrameFiller_new(width, frame, 0);

    if (filler == NULL)
    {
        QRraw_free(raw);
        free(frame);
        return NULL;
    }

    /* inteleaved data and ecc codes */
    for (i = 0; i < raw->dataLength + raw->eccLength; i++)
    {
        code = QRraw_getCode(raw);
        bit = 0x80;

        for (j = 0; j < 8; j++)
        {
            p = FrameFiller_next(filler);

            if (p == NULL)
                goto EXIT;

            *p = 0x02 | ((bit & code) != 0);
            bit = bit >> 1;
        }
    }

    QRraw_free(raw);
    raw = NULL;
    /* remainder bits */
    j = QRspec_getRemainder(version);

    for (i = 0; i < j; i++)
    {
        p = FrameFiller_next(filler);

        if (p == NULL)
            goto EXIT;

        *p = 0x02;
    }

    /* masking */
    if (mask == -2)  // just for debug purpose
    {
        masked = (unsigned char*)malloc(width * width);
        memcpy(masked, frame, width * width);
    }
    else if (mask < 0)
    {
        masked = Mask_mask(width, frame, input->level);
    }
    else
    {
        masked = Mask_makeMask(width, frame, mask, input->level);
    }

    if (masked == NULL)
    {
        goto EXIT;
    }

    qrcode = QRcode_new(version, width, masked);

EXIT:
    QRraw_free(raw);
    free(filler);
    free(frame);
    return qrcode;
}

__STATIC QRcode* QRcode_encodeMaskMQR(QRinput* input, int mask)
{
    int width, version;
    MQRRawCode* raw;
    unsigned char* frame, *masked, *p, code, bit;
    FrameFiller* filler;
    int i, j;
    QRcode* qrcode = NULL;

    if (!input->mqr)
    {
        errno = EINVAL;
        return NULL;
    }

    if (input->version <= 0 || input->version > MQRSPEC_VERSION_MAX)
    {
        errno = EINVAL;
        return NULL;
    }

    if (input->level > QR_ECLEVEL_Q)
    {
        errno = EINVAL;
        return NULL;
    }

    raw = MQRraw_new(input);

    if (raw == NULL)
        return NULL;

    version = raw->version;
    width = MQRspec_getWidth(version);
    frame = MQRspec_newFrame(version);

    if (frame == NULL)
    {
        MQRraw_free(raw);
        return NULL;
    }

    filler = FrameFiller_new(width, frame, 1);

    if (filler == NULL)
    {
        MQRraw_free(raw);
        free(frame);
        return NULL;
    }

    /* inteleaved data and ecc codes */
    for (i = 0; i < raw->dataLength + raw->eccLength; i++)
    {
        code = MQRraw_getCode(raw);

        if (raw->oddbits && i == raw->dataLength - 1)
        {
            bit = 1 << (raw->oddbits - 1);

            for (j = 0; j < raw->oddbits; j++)
            {
                p = FrameFiller_next(filler);

                if (p == NULL)
                    goto EXIT;

                *p = 0x02 | ((bit & code) != 0);
                bit = bit >> 1;
            }
        }
        else
        {
            bit = 0x80;

            for (j = 0; j < 8; j++)
            {
                p = FrameFiller_next(filler);

                if (p == NULL)
                    goto EXIT;

                *p = 0x02 | ((bit & code) != 0);
                bit = bit >> 1;
            }
        }
    }

    MQRraw_free(raw);
    raw = NULL;

    /* masking */
    if (mask < 0)
    {
        masked = MMask_mask(version, frame, input->level);
    }
    else
    {
        masked = MMask_makeMask(version, frame, mask, input->level);
    }

    if (masked == NULL)
    {
        goto EXIT;
    }

    qrcode = QRcode_new(version, width, masked);

EXIT:
    MQRraw_free(raw);
    free(filler);
    free(frame);
    return qrcode;
}

QRcode* QRcode_encodeInput(QRinput* input)
{
    if (input->mqr)
    {
        return QRcode_encodeMaskMQR(input, -1);
    }
    else
    {
        return QRcode_encodeMask(input, -1);
    }
}

static QRcode* QRcode_encodeStringReal(const char* string, int version, QRecLevel level, int mqr, QRencodeMode hint,
                                       int casesensitive)
{
    QRinput* input;
    QRcode* code;
    int ret;

    if (string == NULL)
    {
        errno = EINVAL;
        return NULL;
    }

    if (hint != QR_MODE_8 && hint != QR_MODE_KANJI)
    {
        errno = EINVAL;
        return NULL;
    }

    if (mqr)
    {
        input = QRinput_newMQR(version, level);
    }
    else
    {
        input = QRinput_new2(version, level);
    }

    if (input == NULL)
        return NULL;

    ret = Split_splitStringToQRinput(string, input, hint, casesensitive);

    if (ret < 0)
    {
        QRinput_free(input);
        return NULL;
    }

    code = QRcode_encodeInput(input);
    QRinput_free(input);

    return code;
}

QRcode* QRcode_encodeString(const char* string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
    return QRcode_encodeStringReal(string, version, level, 0, hint, casesensitive);
}

QRcode* QRcode_encodeStringMQR(const char* string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
    return QRcode_encodeStringReal(string, version, level, 1, hint, casesensitive);
}

static QRcode* QRcode_encodeDataReal(const unsigned char* data, int length, int version, QRecLevel level, int mqr)
{
    QRinput* input;
    QRcode* code;
    int ret;

    if (data == NULL || length == 0)
    {
        errno = EINVAL;
        return NULL;
    }

    if (mqr)
    {
        input = QRinput_newMQR(version, level);
    }
    else
    {
        input = QRinput_new2(version, level);
    }

    if (input == NULL)
        return NULL;

    ret = QRinput_append(input, QR_MODE_8, length, data);

    if (ret < 0)
    {
        QRinput_free(input);
        return NULL;
    }

    code = QRcode_encodeInput(input);
    QRinput_free(input);

    return code;
}

QRcode* QRcode_encodeData(int size, const unsigned char* data, int version, QRecLevel level)
{
    return QRcode_encodeDataReal(data, size, version, level, 0);
}

QRcode* QRcode_encodeString8bit(const char* string, int version, QRecLevel level)
{
    if (string == NULL)
    {
        errno = EINVAL;
        return NULL;
    }

    return QRcode_encodeDataReal((unsigned char*)string, strlen(string), version, level, 0);
}

QRcode* QRcode_encodeDataMQR(int size, const unsigned char* data, int version, QRecLevel level)
{
    return QRcode_encodeDataReal(data, size, version, level, 1);
}

QRcode* QRcode_encodeString8bitMQR(const char* string, int version, QRecLevel level)
{
    if (string == NULL)
    {
        errno = EINVAL;
        return NULL;
    }

    return QRcode_encodeDataReal((unsigned char*)string, strlen(string), version, level, 1);
}


/******************************************************************************
 * Structured QR-code encoding
 *****************************************************************************/

static QRcode_List* QRcode_List_newEntry(void)
{
    QRcode_List* entry;

    entry = (QRcode_List*)malloc(sizeof(QRcode_List));

    if (entry == NULL)
        return NULL;

    entry->next = NULL;
    entry->code = NULL;

    return entry;
}

static void QRcode_List_freeEntry(QRcode_List* entry)
{
    if (entry != NULL)
    {
        QRcode_free(entry->code);
        free(entry);
    }
}

void QRcode_List_free(QRcode_List* qrlist)
{
    QRcode_List* list = qrlist, *next;

    while (list != NULL)
    {
        next = list->next;
        QRcode_List_freeEntry(list);
        list = next;
    }
}

int QRcode_List_size(QRcode_List* qrlist)
{
    QRcode_List* list = qrlist;
    int size = 0;

    while (list != NULL)
    {
        size++;
        list = list->next;
    }

    return size;
}

#if 0
static unsigned char QRcode_parity(const char* str, int size)
{
    unsigned char parity = 0;
    int i;

    for (i = 0; i < size; i++)
    {
        parity ^= str[i];
    }

    return parity;
}
#endif

QRcode_List* QRcode_encodeInputStructured(QRinput_Struct* s)
{
    QRcode_List* head = NULL;
    QRcode_List* tail = NULL;
    QRcode_List* entry;
    QRinput_InputList* list = s->head;

    while (list != NULL)
    {
        if (head == NULL)
        {
            entry = QRcode_List_newEntry();

            if (entry == NULL)
                goto ABORT;

            head = entry;
            tail = head;
        }
        else
        {
            entry = QRcode_List_newEntry();

            if (entry == NULL)
                goto ABORT;

            tail->next = entry;
            tail = tail->next;
        }

        tail->code = QRcode_encodeInput(list->input);

        if (tail->code == NULL)
        {
            goto ABORT;
        }

        list = list->next;
    }

    return head;
ABORT:
    QRcode_List_free(head);
    return NULL;
}

static QRcode_List* QRcode_encodeInputToStructured(QRinput* input)
{
    QRinput_Struct* s;
    QRcode_List* codes;

    s = QRinput_splitQRinputToStruct(input);

    if (s == NULL)
        return NULL;

    codes = QRcode_encodeInputStructured(s);
    QRinput_Struct_free(s);

    return codes;
}

static QRcode_List* QRcode_encodeDataStructuredReal(
    int size, const unsigned char* data,
    int version, QRecLevel level,
    int eightbit, QRencodeMode hint, int casesensitive)
{
    QRinput* input;
    QRcode_List* codes;
    int ret;

    if (version <= 0)
    {
        errno = EINVAL;
        return NULL;
    }

    if (!eightbit && (hint != QR_MODE_8 && hint != QR_MODE_KANJI))
    {
        errno = EINVAL;
        return NULL;
    }

    input = QRinput_new2(version, level);

    if (input == NULL)
        return NULL;

    if (eightbit)
    {
        ret = QRinput_append(input, QR_MODE_8, size, data);
    }
    else
    {
        ret = Split_splitStringToQRinput((char*)data, input, hint, casesensitive);
    }

    if (ret < 0)
    {
        QRinput_free(input);
        return NULL;
    }

    codes = QRcode_encodeInputToStructured(input);
    QRinput_free(input);

    return codes;
}

QRcode_List* QRcode_encodeDataStructured(int size, const unsigned char* data, int version, QRecLevel level)
{
    return QRcode_encodeDataStructuredReal(size, data, version, level, 1, QR_MODE_NUL, 0);
}

QRcode_List* QRcode_encodeString8bitStructured(const char* string, int version, QRecLevel level)
{
    if (string == NULL)
    {
        errno = EINVAL;
        return NULL;
    }

    return QRcode_encodeDataStructured(strlen(string), (unsigned char*)string, version, level);
}

QRcode_List* QRcode_encodeStringStructured(const char* string, int version, QRecLevel level, QRencodeMode hint,
                                           int casesensitive)
{
    if (string == NULL)
    {
        errno = EINVAL;
        return NULL;
    }

    return QRcode_encodeDataStructuredReal(strlen(string), (unsigned char*)string, version, level, 0, hint, casesensitive);
}

/******************************************************************************
 * System utilities
 *****************************************************************************/

void QRcode_APIVersion(int* major_version, int* minor_version, int* micro_version)
{
    if (major_version != NULL)
    {
        *major_version = MAJOR_VERSION;
    }

    if (minor_version != NULL)
    {
        *minor_version = MINOR_VERSION;
    }

    if (micro_version != NULL)
    {
        *micro_version = MICRO_VERSION;
    }
}

char* QRcode_APIVersionString(void)
{
    return VERSION;
}

void QRcode_clearCache(void)
{
    QRspec_clearCache();
    MQRspec_clearCache();
    free_rs_cache();
}
